Snowball in Hell: Greenland Ice Sheet Record Thaw

May 17, 2016

On April 11, a dramatic early spike in melting of snow and ice at the surface of Greenland’s ice sheet prompted a Danish climate scientist to say that she and her colleagues were “incredulous.”

Now, there has been a second bout of unusual melting.

You can see both of them in the graph above from the National Snow and Ice Data Center, or NSIDC. It charts the percentage of the Greenland Ice Sheet experiencing surface melting. In both cases, the thaw exceeded 10 percent of the ice sheet’s area.

When I noticed the second spike, I reached out by email to Ted Scambos, lead scientist for the NSIDC science team, to get his reaction to what has been happening in the Arctic lately. Here was his reply:

The Arctic is going to go through hell this year. Both the sea ice and the Greenland surface melting. Snow cover will also set a record.

Scambos emphasized that he wasn’t basing his prediction on a rigorous analysis of data. Instead:

I’m going on ‘duck test’ here: if it walks like a duck, and it quacks like a duck…

The April spike was particularly unusual because of its size, and the fact that it occurred so early in the spring.

The second spike peaked on May 12 and appears to be subsiding now. It prompted scientists with the Danish Meteorological Institute, or DMI, to announce that the Greenland melt season had begun in earnest — and that this tied with 1999 as the fifth earliest start on record.

The DMI considers the melt season to have begun when there has been at least three consecutive days during which more than 5 percent of the ice sheet has seen some melting.

As extreme as the April spike was, that episode was not considered the start to the true melt season because it persisted for just shy of three days.

Even so, Ruth Mottram, a DMI climate scientist, did not hold back in her assessment of a melt event involving so much of the ice sheet, so early.

“Scientists at DMI were at first incredulous due to the early date,” she wrote in a post at the Polar Portal, a site jointly run by Danish research institutions. Then the scientists saw observational data confirming that temperatures in some places on the ice sheet were well above freezing — including as high as 50 degrees C (10 degrees C).